Patent GB-555272-A (GB)
Title: Improvements in and relating to escapement mechanism for the carriages of typewriters and like machines
IPC: B41J19/18
Filed: 1942-02-06
Abstract: 555,272. Typewriters &c. PAILLARD & CIE SOC. ANON., E. Feb. 6, 1942, No. 1586. Convention date, Feb. 6, 1941. [Class 100 (iv)] Letter-spacing mechanism.-The fast and loose pawls of an escapement co-operate with separate ratchet-wheels on the shaft of the feed-pinion, the arrangement enabling the teeth of each ratchet-wheel to be shaped in accordance with the requirements of the associated pawl. In the mechanism shown in the Figure, the shaft 2 of the feed-pinion 1 is provided with ratchet-wheels 4, 3, having crown and radial teeth, co-operating with loose and fast dogs 8. 18 respectively. The dog 8 is mounted on a pivot 9 on a slide 10 and is provided with a pin 14 co-operating with a finger 15 on a rock-shaft 16 which is provided with an arm 16a carrying the pawl 18. The rock-shaft is provided also with a roller 17 co-operating with the universal bail, and an arm 60 connected to the space-bar. The slide 10 is urged to the right by a spring 5 and co-operates for variable-spacing with a movable stop 44 or 45 or a fixed stop 51. On depression of a typing-key or the space-key, the pawl 8 is released from the ratchet-wheel 4, the pawl 18 engages the ratchet-wheel 3, and the slide 10 moves into contact with one of the stops 44, 45, 51. On release of the key, the pawl 18 is released, the pawl 8 is re-engaged by means of a spring 12, the slide is returned, and the shaft 2 performs a letterspacing movement. To permit silent return of the carriage, the ratchet-wheel 4 carries, in a groove, a wire ring 55 having a finger 56 which co-operates with an abutment 72 on the pawl 8 to hold the latter in disengaged position during return of the carriage. During letter-spacing, the finger abuts on a stop 51. The mechanism is mounted as a unit on a block 6 which is secured by screws 49 to the framework 63, rubber plates 61 being interposed. The pawls and the slide 10 may be provided with sounddeadening material. Back-spacing mechanism.-A pawl 23, adapted to co-operate with a ratchet-wheel 24 on the shaft 2, is carried by a bell-crank 22 in connection with a rock-arm 26 operated by the back-spacing key. A stop 28 limits movement of the pawl, and another stop 27 normally holds the pawl out of engagement with the ratchet-wheel. During back-spacing, the slide 10 is locked by co-operation of a lug 74 thereon with a pivoted stop 75 connected to the arm 26. Carriage-releasing mechanism ; tabulating- mechanism.-A lever 33 for depressing the escapement-pawl 8 is coupled to a bail 30 having a tongue 29 actuated by the carriage-releasing lever. The lever 33 is actuated also by a bail 37 abutting on lugs 40 on the denomination-stops 35. The column-stops on the carriage are projected and restored by means of fingers 46, 48 on key-actuated rocking plates. Carriage-brakes.-A pinion 34, normally dis engaged from a pinion 39 on the shaft 2, is carried by a shaft 42 which engages brake-blocks 41 on a spring-urged support 70 abutting on the bail 37. On operation of the bail, by means of the denomination-stops 35, or a key-actuated arm 80, the pinion 39 engages, and the carriage is braked.